Scotch Yoke Piston Control for Combustion Efficiency
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Solution Overview
Problem
Internal combustion engines with direct fuel oil injection face inefficiencies due to piston motion not being synchronized with crankshaft rotation, leading to reduced power and fuel efficiency, as well as harmful emissions.
Innovation Solution
The implementation of a new thermodynamic cycle that controls piston motion to hold them at or near the End Of Stroke during fuel injection and burning, using curved scotch yoke slots and cams on the crankshaft to maintain pistons in an optimal position for extended periods, ensuring complete combustion and efficient fuel use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the piston is allowed to move freely with crankshaft rotation, then the engine structure is simple, but the fuel combustion is incomplete and efficiency is reduced
Solution Approach 1:
The patent applies dynamics by making the piston motion adjustable rather than fixed. The piston can be held at top dead center for a controllable duration through the scotch yoke mechanism with curved slots, allowing the system to adapt piston position to optimization combustion requirements while maintaining mechanical simplicity
2Loss of energy
If the piston is held at top dead center for extended period, then combustion is more complete and efficiency increases, but the crankshaft rotation is delayed reducing power output
Solution Approach 1:
The patent uses periodic action through the scotch yoke mechanism where the piston is held at top dead center during the combustion phase, then released to move downward. This periodic holding and releasing allows complete combustion during the stationary phase while maintaining crankshaft rotation capability for power generation during the moving phase
3Device complexity
If conventional scotch yoke slots are used, then the mechanism is simple, but the piston cannot be held at optimal position for extended time
Solution Approach 1:
The patent applies curvature by designing the scotch yoke slots with curved paths instead of straight lines. The curved slots allow the piston to be held at top dead center for an extended period by following the curved trajectory, enabling the piston to remain at the optimal combustion position longer while maintaining the simplicity of the scotch yoke mechanism
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances fuel efficiency, reduces harmful emissions, and simplifies mechanical design by ensuring all fuel is injected and burned at the most efficient piston position, resulting in higher power output and reduced fuel consumption.
Implementation Method 1
curved scotch yoke slots holding the pistons at or near EOS for an extended time period
Implementation Method 2
cams on crankshaft throws holding the pistons at or near EOS for an extended time period
Implementation Method 3
pistons coming together to form a small spherical combustion chamber with squeeze area on each side to create a swirling charge of air in the chamber
Implementation Method 4
direct fuel oil injected, IC engine cycle that provides... more complete combustion
Data Source
AI summary
An internal combustion engines keeps the pistons at or near the End Of Stroke (EOS) for the whole time or most of the time that fuel is burning or while fuel is injected into the engine. A scotch yoke embodiment includes a curved slot to extend the piston's time at (EOS). A second embodiment includes a cam on the crankshaft and a follower. The shape of the cam extends the piston's time at (EOS).